In the field of implant dentistry, it is known to use both cemented and screw retained restorations. A screw retained restoration has a screw access hole in the occlusal side, through which it is possible to fasten the restoration in the implant using a matching screw.
However, this method of attaching the restoration invariably means that the screw access hole has to be lined up perfectly with the direction of the implant borehole. In some situations, especially for anterior teeth, this arrangement will mean that the screw access hole would become an aesthetic liability.
One way to ameliorate this problem is to use an implant abutment and a cemented restoration. It is known in the field to use a CBCT scan to determine the position and shape of a dental implant.
However, it remains a problem to choose or design an abutment suited for each patient's specific situation.